- From: Dave Crossland <dave@lab6.com>
- Date: Thu, 15 Jul 2010 12:28:26 -0400
- To: www-svg@w3.org
On 14 July 2010 18:26, Doug Schepers <schepers@w3.org> wrote: > Dave Crossland wrote (on 7/14/10 11:47 AM): >> Responding to the minutes: >> On 13 July 2010 22:31, Anthony Grasso<anthony.grasso@cisra.canon.com.au> >> wrote: >>> >>> Catmull-Rom curves >>> <shepazu> http://schepers.cc/?p=243 >>> >>> DS: If you look at that link. If you compare his spiro curves and mine >>> ... his look a lot better >>> ... not sure how he does that >> >> But its so simple. Here's http://levien.com/phd/thesis.pdf is 191 >> pages of Berkeley math PhD thesis to explain! ;p > > Ah, pretty pictures! However, the prose was marred by some squiggly > nonsense shapes that looked something like this: "1 2 3 4 5 6 7 8 9 0". > > I skimmed the paper, and read the intro and conclusion; the section on > interpolation masters (p. 158, Figures 10.9 and 10.10) was particularly > interesting. I think you and I talked about this in Brussels, and I wonder > how well Catmull-Rom curves would perform in this regard? IHNI :) >>> ... the advantage of the Cutmull-Rom curve if you just give a set of >>> points >>> ... It looks like with Spiro curves points have a different >>> characteristic >> >> Spiro has 5 kinds of points. > > So, in that respect, spiro is more akin to a multiple-command path segment > than to one particular command such as a cubic Bézier. In other words, my > experiment with [1] using a combination of (simulated) Catmull-Rom curves > combined with Linetos is rather similar to spiro. Without a screencap on your blog, I'm not sure how you authored the image there. It strikes me that a mature authoring environment for CR curves looks a lot like the "auto smooth node" Inkscape point type. The questions to me are: Are CR curves as smooth as Spiro curves for the same number of points? - No. Are CR curves as easy to author smooth curves with as Spiro curves? - Yes, guess so based on Inkscape auto smooth nodes, unlike normal Beziers. Do CR curves interpolate as smoothly as Spiro curves? - I don't know. > However, he seems like a reasonable guy. :) I look forward to hearing what he says :) > [1] http://schepers.cc/?p=243#spiro-a -- Regards, Dave
Received on Thursday, 15 July 2010 16:29:15 UTC